title: Analysis of HIV subtypes and the phylogenetic tree in HIV-positive samples from Saudi Arabia.
abstract: OBJECTIVE
  To assess the prevalence of HIV-1 genetic subtypes in Saudi Arabia in samples that are serologically positive for HIV-1, and compare the HIV-1 genetic subtypes prevalent in Saudi Arabia with the subtypes prevalent in other countries.
  
  
  METHODS
  Thirty-nine HIV-1 positive samples were analyzed for HIV-1 subtypes using molecular techniques. The study is a retrospective study that was conducted in Dammam, Kingdom of Saudi Arabia, and in Abbott laboratories (United States of America) from 2004 to 2007.
  
  
  RESULTS
  All samples were seropositive for HIV-1 group M. Of the 39 seropositive samples, only 12 were polymerase chain reaction positive. Subtype C is the most common virus strain as it occurred in 58% of these samples; subtype B occurred in 17%; and subtypes A, D and G were found in 8% each. The phylogenetic tree was also identified for the isolates.
  
  
  CONCLUSIONS
  Detection of HIV subtypes is important for epidemiological purposes and may help in tracing the source of HIV infections in the Kingdom of Saudi Arabia.
authors.affiliation: Department of Microbiology, College of Medicine, King Faisal University, PO Box 2114, Dammam 31451, Kingdom of Saudi Arabia. aboeffat@hotmail.com
authors.forename: Alhusain J
authors.initials: AJ
authors.lastname: Alzahrani
mesh_terms: D000328:Adult; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D006801:Humans; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D012529:Saudi Arabia / Q000453:epidemiology